Separation of high molecular organic compound mixtures



July 23, 1957 w. STElN ETAL SEPARATION OF HIGH MOLECULAR ORGANIC COMPOUND MIXTURES Filed Dec. 20, 1955 2 iiii .i .ii lirwwlii sir 1111!!!!1 I IIII I.

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ATTORNEYS United States Patent Ofiice 2,800,493 Patented July 23, 1957 SEPARATION OF HIGH MOLECULAR ORGANIC COMPOUND MIXTURES Werner Stein and Helmut Hartmann, Dusseldorf-Holt hausen, Germany, assignors to Henkel & Cie, G. in. b. H., Dusseldorf-Holthausen, Germany, a corporation of Germany Application December 20, 1955, Serial No. 554,248

23 Claims. (Cl. 260-419) This invention relates to new and useful improvements in the separation of high molecular organic compound mixtures and is a consolidation and continuation in part of our United States applications: Serial No. 293,246, filed January 13, 1952; and Serial No. 379,289, filed September 9, 1953; and Serial No. 401,092, filed December 29, 1953; all of said applications now being abandoned.

High molecular organic compounds such as fatty acids and esters of natural or synthetic origin are usually obtained by way of mixtures, the components of which dilfer from one another by their melting points. Thus the fatty acids and esters are each obtained in the form of mixtures containing components of different melting points. it is generally necessary to separate these mixtures into components of dilferent melting points for further use. This separation has hitherto entailed certain difficulties, disadvantages and drawbacks requiring the use of organic solvents, filtration or hydraulic presses, etc.

One object of this invention is an improved process for the separation of high molecular organic compound mixtures, as for example, fatty acid mixtures and carboxylic acid ester mixtures into components of different melting points.

A further object of this invention comprises such a separation without the use of organic solvents, hydraulic presses or filtering.

The foregoing, and still further objects of the invention, will become apparent from the following description read in conjunction with the drawings in which:

Figure l is a diagrammatic vertical section of an embodiment of an imperforate type centrifuge useful in the practice of the invention,

Figures 2 and 3 are diagrammatic vertical sections of alternate imperforate types of centrifuge baskets useful in the practice of the invention (the driving, bearing and liquid lead-off collector elements having been omitted).

In accordance with the invention, a dispersion of the mixture of the high molecular organic material is formed in an aqueous solution containing a surface active material at a temperature at which the mixture contains solid and liquid components. Thereafter the dispersion is separated by a layer formation into a specifically heavier phase composed of the aqueous solution of the surface active material containing suspended particles of the solid component and a specifically lighter phase composed of the liquid components. The separation of the dispersion into the two phases is elfected by centrifugal action, as, for example, in a centrifugal separator of the imperforate type. The liquid components of the high molecular organic material mixture are directly recovered and the solid components may be recovered by separating the aqueous solution from the solid particles suspended therein.

Suitable raw materials for the practice of the invention are carboxylic acid ester mixes and fatty acid mixes of both natural or synthetic origin.

Natural carboxylic acid esters are predominantly fatty acid esters and particularly glycerides such as are obtained from the fat of vegetable and land and marine animals. Examples of the various types of vegetable fats include coconut oil, palm oil, olive oil, soya bean oil, linseed oil, wood oil and rapeseed oil. Examples of the various types of fats obtained from land animals include beef fat, hog fat and bone fat. Examples of the various different types of fats of marine animals include whale oil, menhaden oil, cod liver oil and herring oil.

Among the natural carboxylic acid esters which contain alcohols other than glycerine as the alcohol component, there may be mentioned, for example, sperm oil which, in addition to glycerides, also contains fatty acid aliphatic alcohol esters as well as the wax esters.

In addition to glycerides, any other desired ester combination may be used such as, for example, are used as softeners which may be produced synthetically.

When the ester mixtures contain solid as well as liquid components at a given temperature, it is often of industrial importance to separate the mixture into components of different melting points as, for example, in the Winterizing of edible oils, the separation of hardened fats. the removal of solid constituents from softeners and the separation of isomeric phthalates, etc.

Fatty acid mixes of natural origin are those which are obtained from the naturally occurring carboxylic acid ester mixes mentioned above. The esters may be split with the aid of water or steam or may be saponified with the aid of caustic while the fatty acids may be liberated from the resulting soaps with the aid of acid. Fatty acid mixtures of synthetic origin may be those obtained, for example, by the oxidation of natural or synthetic paraifins and the isolation of the fatty acids from the oxidation mixture or may be obtained by the oxidation of alcohols such as is, for example, practiced in the hydrogenation of carbon monoxide. Furthermore the synthetic mixtures may be obtained by the oxidation of products which are obtained from the addition of carbon monoxide and hydrogen to olefins resulting in fatty acid mixes well suited to separation by the application of the process in accordance with the invention.

The fatty acid mixtures to be processed according to this invention may preferably contain as main components fatty acids of 830, preferably l0-25 carbon atoms in their molecule. If the ester mixtures are containing as carboxylic acid components fatty acid radicals, these radicals may be derivated from fatty acids of the same molecular size.

All the above mentioned materials are generally obtained as mixtures containing components of varying melting points. These materials are of industrial importance and it is generally necessary to separate the mixtures into components of different melting points for further use.

The invention, however, is not limited to the specific, above enumerated mixtures, but is applicable to all similar mixtures regardless of their source or procedure for obtaining the same, as would be obvious to the skilled artisan since the separation is physical in nature.

In obtaining the dispersion, it is possible to proceed from a completely molten organic material mix or from a more or less solidified mix. In the application of the new method it is necessary that the organic mix to be Separated is present in such a condition that the equeous solution of the surface active material is enabled to substantially displace the liquid organic component from the surface of the solid component. If the starting material is more or less a solidified mixture, it is necessary to subject the mixture to relatively fine comminution by, for example, mechanical treatment such as by way of passing the mixture through sieves, use of stirring devices or roller presses, emulsifiers, ball, pin, hammer, gear disk, impact disk mills or other grinding or cutting devices or comminutors. After this comminution, the solid components of the mixture are present in the form of substantially minute, discrete, i. e., individual non-connected particles.

When using substantially molten mixtures of the organic material, the same is preferably first permitted to par tially solidify. It is of advantage to cool the mixture to a temperature at which the separation is to be effected. The solidification of these mixtures may be carried out while the same are quiescent or while more or less in motion. For the purpose of quiescent solidification, the molten mixture may be poured into forms or molds from which they are removed after their solidification or partial solidification, the same being thereafter subjected to comminution in the manner described above. It is also possible to pass the substantially liquid, i. e., molten mixtures, over cooling rollers whereby the same will be subjected to solidification while substantially at rest on the surface of the cooling roller. The layer of the substantially solidified mixture is stripped from the cooling roller and then comminuted as described above. It is further possible to permit the substantially liquid mixture to cool in suitable containers While being subjected to stirring or agitation. Suitable for this purpose is, for example, an outwardly cooled tube in which the layer of solidifying components of the mixture depositing on the walls of the tube will be continuously removed by a stripper or a scraper.

The solidification may be effected slowly, i. e., over the course of several hours, or may be effected relatively rapidly, as for example, in less than a minute. It may also be carried out in the presence of added, substantially liquid organic compounds such as hydrocarbons, alcohols, esters or carboxylic acids. Preferably such substan tially liquid organic additive materials are used which are relatively easily removable from the components of the organic compounds to be obtained, by reason of their physical properties such as solubility or boiling point. The substantially liquid components of the mixture obtained in the practice of the process in accordance with the invention are especially useful as additives in accordance with this embodiment of the invention and their admixture is of especial advantage in cases for which the mixture which is to be separated contains relatively little of the liquid components. The use of these last mentioned additives has the further advantage that it substantially eliminates the necessity for separate recovery of the additives.

The dispersion of the mixture into the aqueous solution of the surface active material may be effected by adding the comminuted mixture to an aqueous solution of the surface active material or alternately adding the surface active material to the mixture prior to, during or after the comminution. The surface active material may of course, in the same manner, be added at the same time that the comminuted mixture is dispersed in the aqueous solution. In all cases, the ultimate result will be a dis persion of the mixture in an aqueous solution of the surface active material. In this connection it should be noted with emphasis that there results an oil-in-water emulsion and not a water-in-oil dispersion. In the formation of this oil-in-water dispersion, the substantially liquid organic components of the mixture are displaced from the surface of the substantially solid organic components of the mixture forming a dispersion of fine particles in which the liquid and solid components are separated one from the other in the solution of the surface active material.

The dispersion in the aqueous solution may be elfected by shaking, stirring or in any other manner assuring intimate contact between the organic mixture and the aqueous solution.

In many cases it is desirable to use for this purpose such devices as homogenizers or emulsifiers of conventional construction. In many cases it is possible to effect comminution of the organic mixture, as well as where desired the addition of the substantially liquid, organic materials, together with the dispersification of the herein mentioned aqueous solution of the surface active material in a single operation. A further modification of the process in accordance with the invention comprises the incorporation of an equeous solution of surface active materials into the substantially molten mix of the organic materials to be separated and the cooling of the mixture while mechanically working the same. Such mechanical working may, for example, be effected in the same manner as herein above described for the cooling of the substantially molten mixtures or for the production of the dispersion. In this manner it is possible to obtain the substantially solid, organic component of the mixture in an especially fine distribution.

The surface active materials tend to serve the purpose of reducing the interfacial tension between the high molecular organic material and the aqueous medium. Thus any known or conventional surface active material which is chemically inert with respect to the other components in the dispersion may be used. Surface active materials are organic compounds which contain hydrophobic and hydrophilic groups in the molecules. Suitable hydrophilic or water solubilizing groups are, for example, multiple free hydroxyl groups, polyether chains, sulfonic acid and sulfonic acid semi-ester groups and others. Examples of suitable surface active materials include alkylphenolpolyglycol ether, alkylsulfonate, fatty alcohol sulfate, alkylbenzyl sulfonate. Examples of surface active materials having acid water solubilizing groups include alkylbenzyl sulfonates, alcohol sulfates, alkylsulfonates, sulfated fatty acid monoglycerized and soaps including particular soaps of organic basis such as mono-di or tri-ethanolamine. Surface active substances having basic Water solubilizing groups are known as cation active compounds. Of special importance are substances of this type containing quaternary nitrogen atoms for example alkylpyridinium. As examples of surface active materials having non-salt forming water solubilizing groups, there may be mentioned alkylene oxide addition products of high molecular compounds having a mobile hydrogen atom, for example the polyglycol ethers of aliphatic alcohols or alkylphenols as well as polyglycol esters and fatty acids. The surface active agents which may be used in accordance with the invention are, of course, not limited to the above described and any of the known or conventional agents may be used, as for example, those described in the publications: Surface Active Agents by A. M. Schwartz and I. W. Perry, New York, 1949; Encyclopedia of Surface Active Agents,"

' I. P. Sisley and P. I. Wood, New York, 1952; Surface Active Agents by C. B. E. Young and K. W. Coons, Brooklyn, 1945; and A. Chwala Textilhilfsmittel, Wien, 1939, and in U. S. P. 2,396,278.

When the organic mixture being separated is a fatty acid mixture, relatively small amounts of basically reacting materials may be added to the mixture of fatty acids so that relatively small amounts of fatty acid salts are obtained which may serve as a surface active material in accordance with the invention. The surface active materials may also be formed in this manner in connection with the treatment of ester mixtures, particularly natural fats which may contain some free fatty acids.

The amounts and concentration of the surface active material to be used depends in each case upon their surface active properties. Generally concentrations of at least 0.05% preferably of about 0.1-5% of the surface active material calculated by weight of the aqueous medium will give good results.

The properties such as the interfacial activity of the surface active aqueous solution can be influenced by the addition of electrolytes being inert-to the other components of the dispersion. Electrolytes are frequently present in the form of sodium sulfate or sodium chloride in technical surface active substances. Furthermore, other salts, such as magnesium salts, calcium salts or aluminum salts, are suitable as additions. The action of the electrolyte addition to the state of solution of the surface active material, however, is not limited to specific cations such as alkalis or alkali earths nor to specific anions such as chlorides, sulfates or nitrates. There may also be of importance, electrolytes which prevent the corrosion of metallic material, for example nitrites and salts, of such acids of phosphorus which contain less water of constitution than ortho phosphoric acid as well as any desired mixture of such electrolytes. The fact that the action of the electrolyte addition is not specific to the alkali or alkali earth salts may be noted, for example, from the fact that the same effects are obtained, for instance, by the addition of nickel chloride.

It should be understood, however, that no salts are to be used which form substantially insoluble precipitates with the surface active material. The amount of the aqueous solution of the surface active material used is preferably held within the range of about 0.5- parts by weight of water for each part by weight of the high molecular organic material mixture.

In addition to the wetting action of the aqueous solution of the surface active material which wets the surface of the discrete particles of the organic material, and displaces the liquid particles adhering thereto, the aqueous solution has an emulsifying power. The emulsifying power of the aqueous solution should not be permitted to rise too greatly since, in this case, the emulsification effect would be so strong as to cause difficulties in the subsequent separation of the liquid and solid organic material particles requiring an excessive amount of time. Thus, for example, if the particles to be separated were fed into a centrifuge with an exceedingly great emulsifying power being present in the dispersion, the centrifugal separation would take an exceedingly long time and a correspondingly small through-put in the centrifuge would be obtained. To a certain extent, the ratio of the wetting to emulsifying power of the aqueous solution of the surface active material is controlled by the nature and quantity of the particular surface active material selected and may also be controlled to a certain extent by the addition of the electrolytes and/or organic solvents. In accordance with a preferred embodiment of the invention, however, protective colloids are additionally added to the aqueous solution of the surface active material. These protective colloids have been found to be particularly effective in favorably controlling the ratio of wetting to emulsifying power of the aqueous phase by permitting the concentration of the surface active material to be kept at a minimum whereby a minimum emulsifying effect is produced. Thus with the addition of the protective colloid a reduction of the concentration of the surface active material in the aqueous solution is possible while at the same time allowing sufficient wetting effect but substantially reducing the emulsifying effect.

The term protective colloids" is used herein and in the claims to designate any inorganic and organic substances which are soluble, insoluble or capable of swelling in water and which are able to increase the viscosity of the aqueous phase. Inorganic protective colloids consist of a large number of mucilaginous or fioccnlent precipifates which frequently remain suspended in colloidal form in water or only settle out slowly. Examples of inorganic protective colloids include swelling clays, microcrystalline silica and other materials which will remain suspended in colloidal form in Water or only settle out slowly. Completely water soluble compounds, as for example salts of polymeric phosphoric acids, are also suitable for the purpose of the invention. Organic protective colloids can be of natural or synthetic origin. Glue, gelatins or other proteins, tragacanth, pectins, alginates, etc. are examples of protective colloids of natural origin. Protective colloids of synthetic origin include high molecular liquid or wax-like polyglycol ethers, polyacrylates, cellulose glycolates, methyl celluloses, etc. The properties of colloidal substances can be controlled by the number of water solubilizing groups present in the molecules and by the non-hydrophilic functional groups which are also possibly present. As examples of compounds contained in these groups there may be mentioned copolymers of methacrylic acid and methacryl-ates as well as cthoxycellulose glycolates. There may furthermore be mentioned formaldehyde condensation products, phenols, melamine or urea, particularly when there is concerned non-setting condensates which contain water solubilizing groups in the molecule, for example sulfonic acid groups.

In general, protective colloids which contain salt forming .groupsjn the molecules are of particular importance. The concentration of the protective colloids in the aqueous phase may vary within wide limits with concentrations as low as 0.1% being effective and concentrations as high as 7% by weight being permissible.

The optimum quantity of the surface active material, the liquid organic compounds, the electrolytes and the protective colloids, as well as the fineness of comminution and the nature of the treatment with the aqueous solution of the surface active materials may be easily determined by preliminary tests.

By varying the operating conditions such as the nature and manner of the cooling, the separating temperature, the nature and quantity of the liquid organic compounds or their mixtures added, both the consistency of the mixture to be separated and the composition of the solid and liquid components can be influenced.

In certain cases it may be necessary to effect the separation of the organic mixture at temperatures below 0 C., as for example when Winterizing edible oils. In these cases substances which reduce the freezing point must be added to the aqueous solution of the surface active material. Inorganic electrolytes are only suitable for this purpose to a limited extent. It is preferable to use conventional anti-freeze compounds such as polyvalent alcohols or the diflicultly volatile derivatives such as ethylene glycol, glycerine, polyglycerine, polyglycols or their partial esters.

The separation of the dispersion of the organic mixture in the aqueous solution may be effected in certain cases merely by allowing the dispersion to stand whereby the upper phase of the liquid portions of the organic mixture forms along with a lower phase containing the aqueous solution with the dispersed particles of the solid component of the organic mixture. By decanting the layers, products may be very simply recovered.

In accordance with the preferred embodiment of the invention, however, the dispersion is separated into the layers by centrifugal action. For this purpose centrifuges of the imperforate type are used, i. e., those in which the outer walls of the centrifugal bowl or centrifuge basket are solid as distinguished from the so-called perforate centrifuges in which the walls of the centrifuge or the centrifuge basket walls are perforated or otherwise permeable. Thus in the imperforate type centrifuge the solid phase is not retained by way of a sieve, screen or filter but both phases are separated from one another Within the centrifuge by reason of their specific gravity. With the use of the centrifuge the separation into layers of the dispersion which may, under certain circumstances, take place very slowly or not at all, can be greatly accelerated.

The drawings exemplify illustrated embodiments of the centrifuge or centrifugal bowls or baskets usable in the practice of the process in accordance with the invention for the centrifugal separation of the organic material mixes such as the fatty acid mixes, or the carboxylic acid ester mixes, without it being intended, however, to limit the application of the novel method to the particular centrifuge or centrifugal basket types there depicted.

Referring to the diagrammatic representation of the interior of the centrifuge basket as illustrated in Figure l, the centrifuge basket 1 is mounted on shaft 2. Upon operation of the centrifuge, i. e., rotation in the direction of the arrow 20, there is preferably first added through the feed duct 3 an aqueous solution of the surface active substance and not containing the organic material mix such as the fatty acid, ester or alcohol mix. This is advantageously done to build up the layer 5 of specifically heavier liquid to a level beyond the annular space or opening 5a defined between the ring 7 and the outer wall 4 of the centrifuge basket 1. The substantially continuous feed of this solution without organic mix is adjusted to a rate of addition at which the same is continuously discharged from stripping duct 8 thereby assuring the complete submersion within the liquid of the annular space 50. The feed is then switched to the aqueous sur face active solution containing the dispersed organic material mix. With continued feeding of the dispersion. the specifically heavier solid particles containing aqueous solution is banked against the outer basket wall 4 while the specifically lighter substantially liquid organic materials form an inner layer superimposed upon the specifically heavier layer of liquid. As the inner layer of substantially liquid organic material builds up, it will finally establish a balance with the outer layer which may ultimately assume, for instance, the position of layers 5 and 6 (Figure l) the inner layer having built up to reach the intake of stripping duct 9 and the substantially liquid fatty acids are thereafter continuously discharged out of this last mentioned stripping duct while the aqueous dispersion of the substantially solid particles is continuously discharged through stripping duct 8. Ring member 7 prevents the specifically lighter phase from entering the space above the ring member.

Figure 2 shows the centrifuge body It being essentially tubular in construction and being provided with the feed duct 11 for passing the dispersion into the interior of the centrifuge from the bottom thereof. After introducing the dispersion in accordance with the invention through the feed duct 11, the same is separated into the specifically heavier and the specifically lighter phase as above pointed out. In this case the two phases may, for instance, assume the layers indicated in dotted outline and identified by the numerals 12 and 13. In the upper portion of the centrifuge, the two phases are kept from interfering with one another in their separate discharge from the centrifuge by the disk or ring member 14. The latter is preferably mounted on the tubular member 17 and defines with its outer rim the annular space or opening 120 for the passage of specifically heavier liquid into the space above the disk member 14. Also in this case it may be of advantage to start the operations by first using a capillarily active aqueous solution not containing any organic material mix including one that may be derived from a previous separation and containing only the dispersed substantially solid particles. Upon continued addition of the surface active aqueous dispersion of organic material mix into the centrifuge material by way of the feed duct 11, separation into the specifically heavier and the specifically lighter phase occurs resulting in the layer separation illustrated by numerals 12 and 13 as above indicated the layer 12 continuously passing through the annular space 120 into the portion above the disk or ring member 14 thence into the tubuiar member 15 being discharged through the duct 16. As the inner layer 13 of specifically lighter liquid builds up, the same is finally continually discharge by way of the interior of the tubular member 17 and the duct 18.

Figure 3 shows a further alternative type centrifuge useful for the practice of the invention. The centrifuge body 19 carries at the upper end thereof a smaller diameter extension 24 provided with the discharge opening 25. The large diameter centrifuge body 19 is provided at its upper end with the discharge opening 23. The operation of this centrifuge is substantially similar to that described in Figure 2, the dispersion of organic material being fed into the interior of the centrifuge by way of the feed duct 20, being there separated into the specifically heavier and lighter layers 21, 22 which are then separately discharged by way of the discharge openings 23 and 25 respectively. When utilizing this construction, care should be taken in contrast to the constructions illustrated in Figures 1 and 2 that the amount of dispersion passed into the centrifuge by way of the feed duct 20 is sufficiently large to assure an appreciable distance of the interface between the layers 21 and 2.2 from the respective openings 23 and 25. it is also possible and in many cases of advantage, particularly for high separating efficiency to use conventional plate or disk sets in the centrifuge.

in some cases it is desirable to permit the dispersion to flow into the centrifuge in such a manner that a strong acceleration of the dispersion and/or a strong turbulence is avoided insofar a is possible. in most situations, however, this is not necessary.

Inasmuch as the specific weight of the substantially solid organic components of the dispersion separated in accordance with the invention lies between the specific gravity of the aqueous solution of the surface active substances and the specific gravity of the substantially liquid organic components, it should have been expected that when centrifuging the dispersion the substantially solid organic components would partly pass into the aqueous solution and partly into the substantially liquid organic components. In that event the specific gravities of the individual components of the mix should have been ex pected to have formed an intermediate layer composed of a mixture of substantially solid and liquid organic components. A separation by centrifugal action of an organic mix in a substantially continuous operation would then have become impossible because such intermediate layer would have become increasingly larger with continuing feed of further amounts of the original dispersion of organic material mix eventually causing discharge of a mixture through the individual exits instead of the arated organic components. Surprisingly, however, no such difficulty is encountered so that it is possible against expectations to continuously subject a dispersion of organic material mix to centrifugal action and to continuously obtain a substantially complete centrifugal separation of the entire dispersion into the individual substantially solid and substantially liquid organic components. Smail amounts of relatively low boiling solvents that may be contained in the liquid organic components after separa tion may be normally readily removed by heating. The substantially solid organic components may be recovered from their aqueous solution or dispersion by any suitable means such as, for example, filtration or by heating of the suspension to temperatures above the melting point of the substantially solid components. The aqueous solution of surface active materials may be reused for the preparation of new amounts of dispersions of organic material mixes to be separated in accordance with the invention.

The properties of the resulting substantially liquid or substantially solid organic components and especially the solidification or turbidity point of the liquid and the melting point of the solid components are dependent upon the temperature by which the working up and separation of the mixture is effected. After complete separation of the components of the mixture it is furthermore possible to repeat the steps of the separatory process in accordance with the invention, the separated solid components being worked up at a higher temperature and the separated lliquid components at a lower temperature. In this manner there is obtained an extensive melting and solidi- *9 fication point fractionation of the products, it being pos sible to recycle the intermediate fractions to the starting material.

The following examples are given to further illustrate the invention and not to limit the same. In some of the examples, the iodine number is given for identification instead of the solidification point. This has been done since on the one hand the solidification point is dependent on the degree of saturation, and, on the other hand, the iodine number indicates the different separating effects more sensitively than does the solidification points.

Example 1 A tallow fatty acid (acid number 205, saponification number 206, iodine number 59) was pressed at 22 C. through a disk impact mill with the aid of a feed worm and was thereafter pressed through a hair sieve. The acid was then intensively stirred at the same temperature with one half by weight of an aqueous solution containing 0.5% by weight of the sodium salt of a fatty alcohol sulfate of a carbon chain length Cur-C14, 2% by weight of sodium chloride and 0.5% by weight of NazSOr. The resulting dispersion of substantially solid and liquid fatty acid particles in the aqueous solution was thereafter centrifugally separated in a continuously operating centrifuge of the imperforate type provided with stripping ducts for two specifically differing components and having a diameter of about 30 cm. The centrifuge operated at an R. P. M. of about 3000. The centrifugal separation produced oleic acid (iodine number 82) on the one hand and a suspension of stearic acid in aqueous solution on the other. When heated to 80 C., the stearic acid suspension yielded a top layer of liquid stearic acid (iodine number 10.2) which was drawn off.

Example 2 A substantially liquid mix composed of 80% by weight of tallow fatty acid (solidification point 29.8 C.) and 20% by weight of the oleic material obtained as described in Example 1 was subjected to substantially continuing cooling from 40 C. down to C. thereby obtaining a relatively thinly liquid pulp or slush. For this purpose, an outwardly cooled tube is used in which rotating scrapers continuously stripped the solidifying fatty acid components from the inner surface of the cooling tube. A good dispersion is obtained when stirring this slush with the same amount by weight of aqueous solution of +10 C. and containing 0.5% by weight of the sodium salt of a fatty alcohol sulfate of a carbon chain length of C9C11, 3% by weight of sodium chloride and 0.5% by weight of NazSOq; upon centrifuging this dispersion at the same temperature in a centrifuge of the imperforate type and provided with stripping ducts, as for instance exemplified in the diagrammatic illustration shown in Figure 1, an oleic acid with an iodine number 83.2 and a solidification point of 8.2 C. (Oleic acid as used in the examples is intended to designate a product preponderantly consisting of oleic acid but also including, as the case may be, other unsaturated fatty acids.) The centrifuging results additionally in an aqueous stearic acid suspension which is after its separation heated to about 52 C. and thereafter cooled with stirring to 4647 C. within the course of about one hour. This dispersion is then again subjected at the same temperature to centrifuging in an imperforate type stripping duct centrifuge. thereby obtaining a fatty acid having an iodine number of 27.1 on the one hand and an aqueous stearic acid suspension on the other hand from which by heating to 80 C. a stearic acid separates having an iodine number of 5.1 and a solidification point of 53.1 C.

The oleic acid material obtained by the separation procedure at 10 C. was mixed with the same amount by weight of aqueous solution from which the stearic acid had been removed and the mix was cooled while stirring to a temperature of 3 C. Thereupon the resulting aqueous fatty acid dispersion was centrifuged in a centrifuge of the hereinabove described type having an imperforate basket, the centrifuge being conducted at the same temperature at which the mix had been cooled. In this manner the oleic acid material can be further separated into two components having respectively solidification points of +208 C. and -53 C.

Example 3 A substantially liquid tallow fatty acid (solidification point 38.2 C.) together with an equal amount by weight of an aqueous solution containing 0.1% by weight of the sodium salt of a fatty alcohol sulfate of a chain length of C9-C11 and 0.3% by weight of sodium chloride and 0.1% by weight of sodium sulfate were cooled while stirring from a temperature of 40 C. down to 20 C. The resulting dispersion was subjected to centrifuging in a centrifuge of the imperforate type as hereinabove exemplified, the basket of the centrifuge consisting of an elongated cylinder (diameter 10.5 cm., R. P. M. 14,000); the centrifuging resulted in a substantially liquid component essentially comprising an oleic acid material (iodine number 79); the substantially solid particles suspended in the aqueous solution were separated from the aqueous phase by heating to about 80 C. (solidification point 50.1 0.).

Example 4 A substantially hardened whale oil fatty acid (acid number 198, saponification number 203, iodine number 42, solidification point 39.0 C.) was comminuted between rapidly moving cutters at a temperature of about -20 C. until a substantially pulpy or slushy consistency Example 5 A partially hardened sperm oil fatty acid (acid number 211, saponification number 211, iodine number 61, solidification point 25.2 C.) was treated at +10 C. with an aqueous solution of the composition described in Example 2, the treatment being carried out as being set forth in Example 2 whereupon the resultant dispersion was centrifuga lly separated with the aid of an imperforate type centrifuge as, for instance, specified in Example 1 and provided with stripping ducts. The separated substantially liquid components possessed an iodine number 71 and a solidification point of C. while the substantially solid components had an iodine number of 28 and a solidification point of 44.2 C.

Example 6 A synthetically prepared fatty acid obtained by oxidation in accordance with Fischer-Tropsch-Catsch (acid number 217, saponification number 226, iodine number 21, solidification point 39.6 C.) was heated to about 50 C. After addition of about 5% by weight of methanol the heated fatty acids mix was cooled with stirring slowly to a temperature of +20 C. together with 5 times the amount by weight of the fatty acid of an aqueous solution containing 1% by weight of the sodium salt of a 30% salt-containing technical alkyl benzol sulfonate. The dispersion obtained in this manner was then subjected to centrifuging in a plate or disc type centrifuge of the imperforate basket type (diameter 11 cm., R. P. M. 10,000) whereupon there was obtained a substantially liquid fatty acid on the one hand and a suspension of substantially solid fatty acid in aqueous solution on the other. After separation of methanol residue the substantially liquid fatty acid possessed the following characteristics: acid number 221, saponification number 238, iodine number 35, solidification point 26.3 C. The substantially solid fatty acids were separated from the aqueous solution by filtration and possessed the following characteristics: acid number 198, saponification number 199, iodine number 10.8, solidification point 52.2 C.

Example 7 A fish oil fatty acid (acid number 196, saponification number 198, iodine number 116, solidification point 27.9 C.) was heated to a temperature of 30 C. and was then cooled to a temperature of +6 C. while stirring together with double the amount by weight of an aqueous solution containing by weight of capillarily active polyglycol ether and by weight of magnesium sulfate. The dispersion obtained in this manner yielded after its separation in an imperforate type centrifuge (as described in Example 3) a substantially liquid fatty acid (acid number 191, saponification number 195, iodine number 143, solidification point 0.9 C.) and a suspension of substantially solid fatty acids in the aqueous solution the fatty acids being separated from the latter by heating (characteristics of the obtained substantially solid fatty acid: acid number 201, saponification number 205, iodine number 69, solidification point 40.8 (3.).

Example 8 Cotton oil fatty acid (iodine number 87. solidification I point +334 C.) was cooled in the course of 10 hours while stirring from an initial temperature of about 40 C. down to a temperature of +3 C. together with an equal amount by weight of an aqueous solution containing 0.5% by weight of the magnesium salt of a fatty alcohol sulfate of the chain length CsC11 and 5% by weight of MgSOi. The resultant dispersion of substantially solid and substantially liquid fatty acid components was then passed through a conventional emulsifier whereby the temperature rose to about +7 C. at which temperature the dispersion was subjected to centrifuging in an imperforate type centrifuge provided with stripping ducts as set forth in Example 1. The separated substantially liquid components possessed iodine number 117, and a solidification point of 0.9 C. The substantially fatty acids suspended in the aqueous solution were heated together with the aqueous solution to a temperature of about 52 C. the mixture being thereafter cooled in the course of about 2 hours with stirring to about 48 C. whereupon the resulting dispersion was subjected to centrifuging at the last mentioned temperature in an impenforate type centrifuge provided with stripping ducts. In addition to the components of the latter dis persion that were substantially liquid at the last mentioned operational temperature (solidification point 47.1 C.) there was obtained a suspension of substantially solid fatty acids in the aqueous solution and from which there was separated by heating to about 80 C. a fatty acid having iodine number 28 and a solidification point of 51.6 C.

Example 9 Rapeseed oil fatty acid (solidification point 18.6 C.) was dispersed in the same manner using the same aqueous solution of capillarily active materials as specified in Example 8. The temperature after cooling, in this case, was, however, 0 C. with a rise in temperature after passage through the emulsifier to +4 C. Centrifuging of the dispersion was effected in a centrifuge of the imperforate basket type and provided with stripping ducts at the last mentioned temperature and yielded a substantially liquid component having a solidification point of 1.5' C. and an aqueous dispersion of substantially solid fatty acids which were separated from the aqueous medium by heating to about C. in the form of a liquid layer. The solid fatty acids represented by this layer possessed a solidification point of 32 C.

Example 10 In a tallow fatty acid having a solidification point of 398 C. and an iodine number of 52.3, 1% by weight of a technical wetting agent consisting of a 28% solution of the sodium salt of a fatty alcohol sulfate with a chain length of C10 was dispersed with strong stirring. This mixture was continuously cooled off to about 18 C. in a cooling tube provided with scrapers till a mass of pulpy consistency was formed. The mass was subsequently stirred with equal parts by weight of a 3% aqueous magnesium sulfate solution. As a result a dispersion formed in which, separate from each other, liquid and solid fatty acid sieved particles were present.

The dispersion was then separated in a continuously operating two chamber imperforate centrifuge provided with a stripping disk. The lighter phase which separated consisted of the liquid fatty acids and the heavier phase of the aqueous solution contained suspended therein the solid fatty acid particles. The liquid fatty acid had an iodine number of 84.6 and the solid fatty acids ob tained after melting had an iodine number of 17.3. The ratio of the liquids to solid fatty acid was 52:48.

Example I I One kg. lard, iodine number 50, solidification point 32.2 C., was shaken for a few minutes at 20 C. with the same quantity of a wetting agent solution containing 0.5% of the sodium salt of an aliphatic alcohol sulfate of a chain length of C12C14 and 0.5% N32SO4 and 20% MgSOt until a dispersion had formed. This dispersion was passed through a hair sieve in order to hold back any non-dispersed portions of fat possibly still present and then centrifuged in tubes. After the centrifuging, 0.42 kg. liquid fat (iodine number 67, solidification point +4.7 C.) separated as light layer. The lower, heavy layer contained the wetting agent solution in which the solid fats were suspended, predominantly in the upper part of said layer. Upon heating the aqueous layer, 0.56 kg. solid fats separated out and were removed (iodine number 37, solidification point 37.3 C.).

Example 12 Twenty kg. of the lard referred to in Example 1] were pressed, and at the same time, vigorously stirred at 25 C., through a screen into 50 kg. of a wetting agent solution containing 3% of a technical 30% salt containing alkylbenzol suilfonate paste and 2% NaCl. The homogeneous dispersion which was formed, when separated in a continuously operating skimming centrifuge, gave about 10 kg. of a liquid fat (iodine number 63) on the one hand, and an aqueous suspension of the solid fats (iodine number 34) on the other hand. The molten solid substances (about 8 kg.) which deposit upon heating the aqueous suspension were washed several times With water at 50 C. in order to remove any retained traces of wetting agent as well as the liquid substances. About 2 kg. of fat rcmained as dispersion in the centrifuge.

The centrifuge was operated so that neither a strong acceleration nor turbulence of the dispersion of the ester introduced occurred. This was achieved by introducing the dispersion into the center of a cone-shaped hollow body rotating in the centrifuge over the inner surface of which the dispersion is led from the center of the centrifuge to its periphery and was thus continuously accelerated to peripheral speed.

Example 13 Eight tenths (0.8) of a kg. of the lard mentioned in Example 11 and 0.2 kg. of the liquid substances obtained enema-9a.

in Example 12 were melted together, cooled to 20. C.- over the course of several hours, the mixture attaining the consistency of a thick paste, stirred for a short period of time with an equal quantity of a wetting agent solution containing 0.4% of the magnesium salt. of an aliphatic alcohol sulfate of a chain length of C12Cia, as well as 6% MgSOs, and introduced into centrifuge tubes. The separation of the thinly liquid dispersion in a discontinuously operating centrifuge resulted in 0.57 kg. liquid substance of an iodine number of 62, and 0.42 kg. solid substances with an iodine number of 41.

Example 14 Ten kg. sperm oil without spermaceti (iodine number 70, melting point 17 C.) which had solidified after several hours stirring at C. into a thick, still flowing paste, and the same quantity of a wetting agent solution consisting of 100 grams of a technical 50% sodium salt of an aliphatic alcohol sulfate of the chain length Ci2Ci-i, 500 grams MgSO4, 2000 grams ethylene glycol and 7400 grams water, were stirred for 1 minute at 0 C. and the thinly liquid dispersion produced was thereupon centrifuged in a continuously operating solid wall'centrifuge at the same temperature. A separation took place into liquid portions (4.5 kg., iodine number 80, melting point -3 C.) and into an aqueous suspension containing the solid portions of the sperm oil (about 4.3 kg., iodine number 59, melting point 27 C.). A part ofthe aqueous suspension was heated to 10 C. while stirring over the course of 1 hour and again centrifuged. The liquid portions now separated had an iodine number of 70 and a melting point of 8.5 C. The solid portions still remaining in the aqueous phase and which could be separated by heating had an iodine number of 35 and a melting point of 360 C.

The dispersion was introduced into the centrifuge through a pipe positioned so that tthe dispersion emerged in the vicinity of the centrifugal wall in an approximately tangential direction with respect to the same and in the direction of rotation of the centrifuge with a velocity approximately equal to the peripheral velocity of the centrifuge. In this manner a strong acceleration and turbulence was avoided.

Example 15 A mixture of 1 kg. of the sperm oil mentioned in Example 14 and /2 kg. of a wetting agent solution which contained 1% of the sodium salt of an aliphatic alcohol sulfate of the cabin length C12-C14, as well as 0.5% NazSOi and 5% NiClz was cooled while stirring slowly for several hours from 20 C. to +2 C. The dispersion obtained was thereupon separated in a tube centrifuge at 0 C. into two components. The one component consisted of the portions of the sperm oil liquid at 0 C. (0.63 kg. iodine number 77) while the other contained, suspended in the wetting agent solution, the portions of the sperm oil solid at 0 C. which it was possible to separate by heating (0.33 kg., iodine number 57).

Example 16 Olive oil (iodine number 82, melting point +7 C.) which had been solidified by standing for several days at 0 C. was comminuted at 0 C., by a rapidly operating cutter followed by pressing through a hair screen, into a paste like consistency. Five hundred grams thereof were shaken with the same quantity of wetting agent solution containing 1.0% of a technical 50% sodium salt as an aliphatic alcohol sulfate of the chain length C12C14 at 0 C. and in this connection gave a flowing dispersion which separated by centrifuging in a tube centrifuge. The liquid portions separating as the upper layer (about 260 grams) had an iodine number of 89 and a melting point of -14 C. while the solid portions suspended in the wetting agent solution (about 320 grams) and which could be separated by heating, had an iodine number of 74 and a melting point of +10 C.

Example 17 The olive oil mentioned in Example 16 was cooled Within 12 hours from +20 C. to -5 C. in mixture with twice its quantity of a wetting agent solution consisting of 2% of a technical 50% sodium salt of an aliphatic alcohol sulfate of the chain length C1a-C14, 2% MgSOi, 82% Water and 14% glycerine and thereupon centrifuged in a tube centrifuge. In this connection, the temperature increased to |5 C. The liquid portions separating as upper layer had an iodine number of 87 and a melting point of 4 C., while the solid portions suspended in the wetting agent solution had an iodine number of 79 and a melting point of +9 C.

Example 18 Five hundred grams of lard (iodine number 47) were stirred for 1a hour at 25 C. with the same quantity of an aqueous solution containing 5% of a technical monoglyceride emulsifier (about 14% soap, 4% free fatty acid, 6% water, balance fatty acid glycerides, consisting of monoglycerides and /s of diglycerides). The dispersion formed was thereupon treated in accordance with Example 11 and gave grams of liquid substances (iodine number 61) and 330 grams solid substances (iodine number 43).

Example 19 Five hundred grams of an esterification product from phenoxyacetic acid and sperm oil alcohol, which product can be used as softener (iodine number 44, solidification point 11.6 C.) were cooled within /2 hour while stirring to +2 C. with the same quantity of an aqueous solution containing 0.75% dodecyl-benzyl-diethyl ammonium chloride, 0.75 of a technical sodium alginate and 10% MgSO4 and the dispersion obtained was thereupon centrifuged in tubes. The separation gave as upper layer 245 grams liquid esters (iodine number 54, solidification point +1.3 C.) and after heating the aqueous layer which contained the solid esters in suspended form, there were obtained 250 grams solid esters of an iodine number of 34 and a solidification point of 18.1 C.

Example 20 Two kg. of coconut oil having an iodine number of 9.3 and a solidification point of 21.l C. and a melting point of 25 C. were intimately mixed at a temperature of 20 C. with two kg. of an aqueous solution which contained 2% by weight of a technical 50% sodium fatty alcohol sulfate having a chain length between C12 and C14 and additionally containing 5% MgSO4. The mixing was effected by slow stirring. The mixture was twice screened through a sieve resulting in a thinly liquid dispersion which was centrifuged. As a result of the centrifuging, a lighter liquid fat phase and a heavier layer phase consisting of the aqueous phase containing the solid constituents formed. The two components were obtained in pure form by heating and washing. The liquid constituents had an iodine number of 11.5 and a solidification point of 17.9 C. and the solid components had an iodine number of 5.3, a solidification point of 25.7 C. and a melting point of 29 C. The ratio of liquid to solid components was 70:30. The separated solid fatty constituents constituted an excellent coco butter substitute.

Example 21 Two kg. of hardened coconut oil having an iodine number of 0 and a solidification point of 27.2" C. were treated with a wetting agent solution at 20 C. in the manner described in Example 20 and centrifuged in a laboratory type centrifuge. About 1.1 kg. of the liquid fatty constituents separated with a solidification point of 18 C. A part of the remaining dispersion of the solid fat constituents (solidification point 31.1 C.) in the aqueous wetting agent solution were warmed with stirring to 30 C., stirred for half an hour and again centrifuged in pre-heated glasses in the centrifuge. A further separation occurred with 15% liquid fat constituents separating out (referring to the solid fat constituents separated at 20 C.). The solidification of the liquid constituents in the separation at C. was 28.3 C. and that of the solid constituents was 32.9 C.

Example 22 Unrefined palm oil was continuously cooled in a scraper cooler from to 25 C. The scraper cooler consisted of a tube with 16 litres content cooled externally and provided with rotating scrapers which moved adjacent to the wall. The palm oil was pumped through this tube with a throughput of litres per hour and left the cooler as a thinly liquid mixture of liquid fat constituents with crystals of solid fat constituents finely dispersed therein. The partially solidified fat was subsequently dispersed in an aqueous wetting agent solution in six stirring vessels connected together by overflows in series. In the first stirring vessel the fat was continuously mixed to form a dispersion with half of its amount by weight (25 litres per hour) of an aqueous solution having a temperature of 25 C. which contained 2% of a technical sodium salt of a C10 fatty alcohol sulfate (0.3% active substances) as well as 3% magnesium sulfate. In the next three stirring vessels the dispersion formed in the first stirring vessel was thinned by the addition of 3% magnesium sulfate solution. The added amount consisted of 12.5 litres per hour which was distributed about evenly in the three stirring vessels. The dispersion was thereby thinned to an amount ratio of fat to aqueous solution of 1:075. The next two stirring vessels served for the homogenization of the dispersion by stirring. The so-formed dispersion at a temperature of 25 C. was passed into a solid jacket centrifuge and was therein continuously separated into an aqueous phase containing the solid fat constituents and a liquid fat phase. The amount ratio of solid to fiuid constituents was about 20:80. The starting material and fractions had the following characteristics:

Saponl- Melting Acid fiOtltlOIl Iodine it P nicnt,

Startin matcriub. 2.0 1053 50.1) 37.2 Solid constituents. 1. S 108 30. 7 48. 5 Liquid constituents. 2.1 203 I) 20.0

amounts of solid to liquid fat constituents was about 25:75. The materials had the following characteristics:

Sapnnification Iodine I lt lclting Acid it lotnt,

Liquid constituents.

Example 23 In order to remove small amounts of a high melting constituent from palm oil the first portion of Example 22 was repeated in connection with palm oil having an iodine number of 47.6 and a melting point of 41 C. In the scraper cooler the palm oil was cooled from 45 to 31 C. The temperature of the dispersion in the first stirring vessel was 31 C. and rose to a temperature upon entrance into the centrifuge of 37 C. The following products were obtained:

A solid fat constituent having an iodine number of 22.1 and a melting point of 56 C. and a liquid fat constituent having an iodine number of 49.2 and a melting point of 29 C. The amount ratio of solid to liquid constituents was 6.4:93.6.

Example 24 1 kg. of palm oil having an iodine number of 47.6 and a melting point of 41 C. was cooled while stirring within one hour from 45 to 35 C. and thereafter further stirred for an hour at 35 C. Thereafter the oil was stirred for fifteen minutes with grams of an aqueous solution containing 3% magnesium sulfate as Well as 5% of a technical 50% sodium fatty alcohol sulfate with a chain length of C12-C1s at the same temperature. The centrifuging of the resulting dispersion resulted in an upper phase containing liquid constituents of the palm oil which, after washing with water, had an iodine number of 50 and a melting point of 245 C. and a lower aqueous phase in which the solid oil constituents were dispersed. After melting and separating from the water the solid constituents had an iodine number of 30.5 and a melting point of 53 C. The ratio of liquid to solid constituents was 88:12.

Example 25 Raw coconut fat having a temperature of 35 C. was cooled to 21 C. in the apparatus described in Example 22 with a throughput of 30 kilograms per hour. The

' cooled fat mixture was stirred with /1 its amount by weight of an aqueous solution which contained 0.6 weight percent of a sodium Cm fatty alcohol sulfate and 4% by weight of MgSO4 in the first of the six stirring vessels arranged in series. The resulting dispersion was passed from the stirring vessels into an imperforate type centrifuge and was continuously separated into the liquid fat and the dispersion of solid fat and the aqueous phase at a temperature of 22 C. The separated aqueous phase was then heated to 50 C. so that the solid fat constituents were completely liquified and separated from the aqueous phase in a disk centrifuge. The amount ratio of the higher to lower melting constituents obtained was 28:72. The aqueous wetting agent solution was used after the addition of one-tenth of the weight percent of the wetting agent for a subsequent separation. The separated products had the following characteristics:

SaponilVIt-lting Acid it fieatiun Iodine P niit,

Starting coconut int 11. 9 200 0. 5 23 Solid constituents. 5. 3 27:6 2. J 29 Liquid c nstituents 14. 3 201 1]. 1 10 Palm kernel oil fat 10 r Solid constituents..." Liquid constituents.

The solid constituents obtained in accordance with Examples 25 and 26 were washed with alkali to remove any free acid as a result of which the melting points increased to 30 and 34 C. respectively. The so-pun'fied products had a melting range of only 1 C, and their melting expansion curves showed pronounced peaks at 29-30 C. and 33-34 respectively. The characteristics therefore very closely approximated coconut butter for which they constituted an excellent substitute.

Example 27 Completely melted down raw palm oil kernel oil fat having an acid number of 18, a saponification number of 244 and an iodine number of 15.2 was cooled in a scraper cooler as used in Example 22 of 50 litres content with a throughput of 55 kilograms per hour. The first portion of the scraper was cooled with water to a temperature of 12 C. while the second half was cooled with water to a temperature of 25 C. The exit temperature of the palm kernel oil fat amounted to 24.8 C. The cooled fat mixture was then worked up with 25 kg. per hour of an aqueous solution at 25 C. which contained 0.3% by weight of NaOH and 4% by weight of NazSOa in the first of six stirring vessels connected in series. The free fatty acid present in the raw palm kernel fat formed an alkali soap which acted as a surface active agent and dispersed the fat in the aqueous solution. In the second to fifth stirring vessels, the mixture was thinned in stages with 5.5 kg. per hour in each stage of a 3% Na2SO4 solution. After running through the sixth stirring vessel, the dispersion formed which had a temperature of 25 C. was passed into an imperforate centrifuge in which a separation took place of the liquid fut constituents in the suspension of the solid at constituents in the aqueous phase. After heating to a temperature of about 60 C., 12% based on the raw palm kernel oil fat initially treated of solid constituents were separated. These solid constituents after an alkali refining had a flow melting point of 335 C. and a clear melting point of 33.7 C.

Example 28 Deacidificd cotton seed oil was cooled off with an equal amount of an aqueous solution which contained 0.7% by weight of a technical 30% by weight sodium fatty alcohol sulfate with a chain length of C10 and 4% by weight magnesium sulfate. The mixture was stirred and cooled within half an hour from 20 to 5 C. The dispersion formed was allowed to stand 20 hours at this temperature without stirring. During this time the higher melting constituents crystallized out from the cotton seed oil in the dispersion, subsequently the mixture was separated after stirring for a short period of time at a temperature of 6 C. in an imperforate centrifuge. The aqueous solution with the solid higher melting glycerides suspended therein separated off as the heavy phase. The lighter phase of cotton seed oil was obtained in the yield of about 86% which, after removal of moisture traces, remained entirely clear after standing for 5 /2 hours in ice water, thereby indicating extremely high cold resistance.

Example 29 Molten cotton seed fatty acid, iodine number 95, is cooled with continuous movement in a kneading machine to +15 C. The fatty acid paste obtained thereby is stirred for 5 minutes with an identical quantity of an aqueous solution at the same temperature containing 0.5% of a technical 50% sodium aliphatic alcohol sulfate of a chain length Cue-C14, 5% MgSO i, and the dispersion obtained is charged into centrifuge tubes and centrifuged. After centrifuging for 5 minutes, 2 layers form; the lower layer consists of the aqueous phase with portions of solid fatty solids suspended therein, while the upper layer consists of liquid fatty acid. The example is repeated with various amounts of alginate added imnwiw -1". Alginate Concern Percenthyllcight of Liquid Fatty tration in the A- queous Solution Acids separated Based on the of Surface Active Substances in Weight of the P o r c e nt. b y Entire Disper- Weight sion.

Example 30 grams of a tallow fatty acid, iodine number 55, which has been comminuted at 22 C. to a pasty consistency in a high-speed cutter, were stirred for 10 minutes at the same temperature with the same quantity of an aqueous solution of a wetting agent containing 0.2% of the sodium salt of a technical 50% aliphatic alcohol sulfuric acid semi-ester of the chain length C12C14, 5% MgSO4 and 0.5% sodium alginate, whereupon the dis persion obtained was introduced into centrifuged tubes and centrifuged. 64 grams of liquid fatty acids, iodine number 79, separated as the upper layer, while the lower aqueous layer contained 33 grams solid fatty acids which were separated by melting, iodine number 8.2. A parallel test carried out with the solution of wetting agent without the addition of alginate resulted in solid fatty acids having an iodine number of 20.

Example 31 500 grams of a mixture of animal fatty acids, iodine number 61, acid number 204, were cooled, together with twice the quantity of a solution of wetting agent containing 0.2% of a technical 50% sodium salt of an allphatic alcohol sulfuric acid semi'ester of the chain length C12C15 and 5% MgSOr, within the course of 3 hours with agitation, from 40 to 20 C., whereupon the dispersion produced was separated in a centrifuge in the manner described in Example 30.

The solid portions which separated had an iodine number of 25.8. In parallel tests in connection with which 1% of diifcrcnt protective colloids were furthermore added to each of thc wetting agent solutions, the solid portions separated had the following iodine numbers:

Prater-ti re Colloid Example 32 1 kg. of the fatty acid mixture described in Example 30 was cooled with stirring from 40 to 20 C., forming a fatty-acid paste, which was still fluid, and thereupon stirred together with the same quantity of wetting agent solution containing 0.2% of a technical 50% sodium salt of a fatty-alcohol sulfuric acid scmiester of the chain length C12-C14 MgSO4, as well as 1% of a technical sodium cellulose-glycolate. The dispersion was separated in a tube-type centrifuge. The liquid portions of fatty acid separated, iodine number 85, were separated, and the lower aqueous layer heated so that the solid portions suspended therein, iodine number 18.3, could be melted and separated. Thereupon, 0.2% of the aforementioned sodium aliphatic alcohol sulfate was dissolved in the remaining aqueous phase, which was free of fatty acid and the wetting agent solution was used as described above for a further separation of fresh fatty acid. The solid portions obtained after separation had an iodine number of 19.6. A parallel test with a fresh solution of wetting agent of the same concentration, but without the addition of cellulose glycolate, gave solid portions having an iodine number of 24.2.

Example 33 The fatty acid mixture described in Example 30 was melted and continuously cooled to 20 C., forming a thin pasty mass, in a scraper cooler. 100 kg. thereof were stirred into 60 kg. of wetting agent solution, which contained 1% of an approximately 30% technical sodium-alkylbenzolsulfonate having 10-16 carbon atoms in the alkyl chain, 2% NaCl, and 2% ammonium-polymethacrylate. Thereupon the dispersion produced was further diluted with 140 kg. of a 2% sodium chloride solution and stirred for 10 minutes. The thinly-liquid mixture thus obtained could be continuously separated in an imperforate stripping disc-type centrifuge, 150 kgs. dispersion giving 28 kgs. liquid fatty acids, iodine number 84, on the one hand and a suspension of the solid fatty acids in the aqueous phase on the other hand. By heating the aqueous phase. 20.5 kgs. solid fatty acids separated as the upper liquid layer and could be drawn off. Iodine number of the solid fatty acids: 14.9.

While the invention has been described in detail with reference to certain specific embodiments, various changes and modifications will become apparent to the skilled artisan which fall within the spirit of the invention and the scope of the appended claims.

When using the process of the invention for the production of fats of the cocoa butter type, the starting fats should contain a comparatively high content in C12- fatty acids. The content of Crz-fatty acid radicals should be at least 30, preferably 4055% by weight, calculated on the total fatty acid radicals being present in the start ing glycerides. Fats of such a composition are found in the seed fats of palms. Therefore cocoa fat, palm kernel oil and babassu oil are of special importance as starting materials. These fats are processed in such a manner, that the lower melting fats are separated and that the content in C12-fatty acid radicals is enriched. The higher melting constituent is suited as a substitute for cocoa butter. Preferably, the starting fats are processed in a raw state and the solid constituents are raflinated.

When Winterizing edible oils there are used as starting materials oils, becoming cloudy when cooled on C. for more than 3 hours, preferably for 520 hours. According to the invention, the highcr melting constituents are removed from these oils in such an extent, that the oils do not become cloudy when testing in the said manner. The winterized oils should conform the cold test according to the American Oil Chemists Society Official Method Cc 11-53.

We claim:

1. Method for the separation of organic mixtures selected from the group consisting of mixtures of fatty acids and mixtures of carboxylic acid esters into components of different melting points which comprises forming a dispersion of such a mixture in a sufficient quantity of an aqueous solution of a surface active material substantially inert to the components of said mixture to maintain a continuous aqueous phase at a temperature at which the mixture contains both solid and liquid constituents, thereafter subjecting the dispersion to centrifugal action in an outwardly confined liquid impermeable zone separating the aqueous dispersion into a specifically lighter phase of substantially liquid components of the mixture and a specifically heavier phase of aqueous medium with substantially solid components of the mixture (i; suspended therein, and separately removing at least a portion of at least one of said phases.

2. Method according to claim 1 in which said surface active material has at least one organic hydrophobic radical and one water solubilizing group in its molecule.

3. Method according to claim 2 in which said surface active material is present in an amount of at least 0.05 by weight of its aqueous solution, and in which said aqueous solution is present in said dispersion in an amount from 0.5 to 5 parts by weight for part by weight of the organic mixture.

4. Method according to claim 1 in which said dispersion additionally contains a low boiling liquid organic solvent.

5. Method according to claim 1 in which said dispersion is formed by intimately contacting said aqueous solution of a surface active material with said mixture in substantially completely molten condition and thereafter cooling the resultant intimate mixture to said temperature for said separation.

6. Method according to claim 1 in which said aqueous dispersion additionally contains an electrolyte.

7. Method according to claim 1 in which said aqueous dispersion additionally contains a protective colloid.

8. Method according to claim 7 in which said protective colloid is present in amount up to 7% by weight.

9. Method according to claim 1 in which said aqueous solution of the surface active material containing the separated solid components of said organic mixture is separated from the latter and in which said aqueous solution is reused for the preparation of new dispersion.

10. Method according to claim 1 in which at least one of the separated phases is again subjected to said centrifugal action in the form of said dispersion at a temperature which for said liquid component of said mixture is lower and which for said solid dispersed component of said mixture is higher than said temperature at which the centrifugal separation is effected in the preceeding centrifugal treatment.

11. Method according to claim 1 in which the separated aqueous solution containing said substantially solid dispersed component of the organic mixture is subjected to at least one additional phase separation at a temperature for the dispersion and for the separation higher than the temperature of the preceding separation.

12. Method according to claim 1 in which said aqueous dispersion contains a freezing point depressant for the aqueous medium.

13. Method according to claim 1 in which said mixture is comminuted prior to formation of said dispersion.

14. Method according to claim 1 in which said mixture contains free fatty acid and in which said surface active material is formed in situ by the addition of an alkaline reacting material.

15. Method according to claim 1. in which said surface active material is a member selected from the group consisting of alkylphenol polyglycol ethers, alkyl sulfonates, fatty alkyl sulfates and alkylbenzyl sulfonates.

16. Method according to claim 1 in which said surface active material is initially added to said organic mixture prior to forming said dispersion.

17. Method for the separation of fatty acids from a mixture thereof which comprises subjecting such mixture, which substantially dispersed in a continuous phase aqueous solution of surface active material substantially inert to said fatty acids to outwardly confined centrifugal action at a temperature for the dispersion at which a portion of such fatty acids is in a substantially solid and the remainder in substantially liquid condition, continuing said centrifugal action at substantially said temperature there by forming a first layer comprising said aqueous solution and therein dispersed substantially solid fatty acids and a second layer comprising substantially liquid fatty acids, and separately removing at least a portion of at least one of said layers.

18. Method for the separation of fatty acids from a mixture thereof which comprises substantially continuously feeding a dispersion of such mixture in a continuous phase aqueous solution of a surface active material substantially inert to said fatty acids and at a temperature for the dispersion at which a portion of said fatty acids is in a substantially solid and the remainder in substantially liquid condition, into an outwardly confined centrifugal zone at one section thereof, substantially continuously subjecting such dispersion while substantially at said temperature to centrifugal action in said zone thereby forming therein a first layer comprising said aqueous solution and therein dispersed substantially solid fatty acids and a second layer comprising substantially liquid fatty acids, and substantially continuously removing material from each of said layers at layer sections removed from said zone section of dispersion feed, said feeding of dispersion and removal of layer material being so adjusted that such layers are substantially continuously maintained within said zone.

19. Method for the separation of mixtures of carboxylic acid esters which comprises forming a dispersion of such a mixture in a sufficient quantity of an aqueous solution containing a surface active material to maintain a continuous aqueous phase at a temperature at which said mixture contains solid and liquid esters, and separately recovering solid ester and liquid ester.

20. Method for the separation of carboxylic acid esters from a mixture thereof which comprises subjecting such mixture, while substantially dispersed in a continuous phase aqueous solution of surface active material substantially inert to said carboxylic acid esters to outwardly confined centrifugal action at a temperature for the dispersion at which a portion of such carboxylic acid esters is in a substantially solid and the remainder in substantially liquid condition, continuing said centrifugal action at substantially said temperature thereby forming a first layer comprising said aqueous solution and therein dispersed substantially solid carboxylic acid esters and a second layer comprising substantially liquid carboxylic acid esters, and separately removing at least a portion of at least one of said layers.

21. Method for the separation of carboxylic acid esters from a mixture thereof which comprises substantially continuously feeding a dispersion of such mixture in a continuous phase aqueous solution of a surface active material, substantially inert, to said carboxylic acid esters and at a temperature for the dispersion at which a portion of said carboxylic acid esters is in a substantially solid and the remainder in substantially liquid condition, into an outwardly confined centrifugal zone at one section thereof, substantially continuously subjecting such dispersion while substantially at said temperature to centrifugal action in said zone thereby forming therein a first layer comprising said aqueous solution and therein dispersed substantially solid carboxylic acid esters and a second layer comprising substantially liquid carboxylic acid esters, and substantially continuously removing material from each of said layers at layer sections removed from said zone section of dispersion feed, said feeding of dispersion and removal of layer material being so adjusted that such layers are substantially continuously maintained within said zone.

22. Method for the preparation of cocoa butter substitutes which comprises forming a dispersion of a fat with a comparatively high content in a sufficient quantity of Crz-fatty acid radicals in an aqueous solution con taining a surface active material to maintain a continuous aqueous phase at a temperature at which said fat contains solid and liquid components, separating the dispersion by layer formation into a specifically lighter phase of substantially liquid components of the mixture and a specifically heavy phase of aqueous medium with substantially solid components of the mixture suspended therein, separately removing at least a portion of said heavier phase and recovering the separate solid constituents therefrom as a cocoa butter substitute.

23. Method according to claim 1, in which said surface active material has at least one organic hydrophobic radical and one water solubilizing group in its molecule and is present in amount of about 0.1-5 by weight of its aqueous solution.

References Cited in the file of this patent UNITED STATES PATENTS 

1. METHOD FOR THE SEPARATION OF ORGANIC MIXTURES SELECTED FROM THE GROUP CONSISTING OF MIXTURES OF FATTY ACIDS AND MIXTURES OF CARBOXYLIC ACID ESTERS INTO COMCOMPONENTS OF DIFFERENT MELTING POINTS WHICH COMPRISES FORMING A DISPERSION OF SUCH A MIXTURE IN A SUFFICIENT QUANTITY OF AN AQUEOUS SOLUTION OF A SURFACE ACTIVE MATERIAL SUBSTANTIALLY INERT TO THE COMPONENTS OF SAID MIXTURE TO MAINTAIN A CONTINUOUS AQUEOUS PHASE AT A TEMPERATURE AT WHICH THE MIXTURE CONTAINS BOTH SOLID AND LIQUID CONSTITUENTS, THEREAFTER SUBJECTING THE DISPERSION TO CENTRIFUGAL ACTION IN AN OUTWARDLY CONFINED LIQUID IMPERMEABLE ZONE SEPARATING THE AQUEOUS DISPERSION INTO A SPECIFICALLY LIGHTER PHASE OF SUBSTANTIALLY LIQUID COMPONENTS OF THE MIXTURE AND A SPECIFICALLY HEAVIER PHASE OF AQUEOUS MEDIUM WITH SUBSTANTIALLY SOLID COMPONENTS OF THE MIXTURE SUSPENDED THEREIN, AND SEPARATELY REMOVING AT LEAST A PORTION OF AT LEAST ONE OF SAID PHASES. 